Cancer Treatment Today

The approach of returning to a regimen that obtaining a complete response and was restarted after second line chemotherapy became ineffective, is  not well studied. On kinetic grounds, it might still be effective for cells that were susceptible but dormant when it was initially given. However, there is some older literature that suggests it may be effective. an 1988 paper by Vincent et al looked at Fifteen patients with SCLC who had relapsed off treatment after responding to initial first-line chemotherapy were retreated with the same regiment at relapse. Ten (67%) achieved a further partial response. Median response duration was only 3 months (range 24 months), but similar poor results have been reported for most studies using second-line chemotherapy. Relapse in SCLC does not necessarily imply complete clinical resistance to first-line chemotherapy, and strict clinical criteria are required to demonstrate true non-cross resistance.

There is a British Columbia  guideline that says:
“Level of Evidence: 2

Recurrent SCLC …. Patients with longer remissions, particularly those that are free from progression for six months to one-year may be considered for combination chemotherapy. When the time to progression is long (a year or more) platinum and etoposide may be repeated.”

The plan to retreat is reasonable and supported by somewhat dated but still applicable medical literature. There are no newer references to supply.

S. Cara et al, Retreatment of patients with the same chemotherapy: Implications for clinical mechanisms of drug resistance. Annals of Oncology 12 23-27. 2001

Mark Vincent, Barrie Evans, Ian Smith, First-line chemotherapy rechallenge after relapse in small cell lung cancer, Cancer Chemotherapy and Pharmacology. February 1988, Volume 21, Issue 1,  pp 4548.

http://www.bccancer.bc.ca/health-professionals/professional-resources/cancer-management-guidelines/lung/lung#Salvage-Therapy-for-Relapsed-SCLC-Patients, Revised 3/15/2013.